drivers/acpi/proc.c

   1 #include <linux/proc_fs.h>
   2 #include <linux/seq_file.h>
   3 #include <linux/export.h>
   4 #include <linux/suspend.h>
   5 #include <linux/bcd.h>
   6 #include <asm/uaccess.h>
   7
   8 #include <acpi/acpi_bus.h>
   9 #include <acpi/acpi_drivers.h>
  10
  11 #ifdef CONFIG_X86
  12 #include <linux/mc146818rtc.h>
  13 #endif
  14
  15 #include "sleep.h"
  16
  17 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
  18
  19 /*
  20  * this file provides support for:
  21  * /proc/acpi/alarm
  22  * /proc/acpi/wakeup
  23  */
  24
  25 ACPI_MODULE_NAME("sleep")
  26
  27 #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || !defined(CONFIG_X86)
  28 /* use /sys/class/rtc/rtcX/wakealarm instead; it's not ACPI-specific */
  29 #else
  30 #define HAVE_ACPI_LEGACY_ALARM
  31 #endif
  32
  33 #ifdef  HAVE_ACPI_LEGACY_ALARM
  34
  35 static u32 cmos_bcd_read(int offset, int rtc_control);
  36
  37 static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
  38 {
  39         u32 sec, min, hr;
  40         u32 day, mo, yr, cent = 0;
  41         u32 today = 0;
  42         unsigned char rtc_control = 0;
  43         unsigned long flags;
  44
  45         spin_lock_irqsave(&rtc_lock, flags);
  46
  47         rtc_control = CMOS_READ(RTC_CONTROL);
  48         sec = cmos_bcd_read(RTC_SECONDS_ALARM, rtc_control);
  49         min = cmos_bcd_read(RTC_MINUTES_ALARM, rtc_control);
  50         hr = cmos_bcd_read(RTC_HOURS_ALARM, rtc_control);
  51
  52         /* If we ever get an FACP with proper values... */
  53         if (acpi_gbl_FADT.day_alarm) {
  54                 /* ACPI spec: only low 6 its should be cared */
  55                 day = CMOS_READ(acpi_gbl_FADT.day_alarm) & 0x3F;
  56                 if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
  57                         day = bcd2bin(day);
  58         } else
  59                 day = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
  60         if (acpi_gbl_FADT.month_alarm)
  61                 mo = cmos_bcd_read(acpi_gbl_FADT.month_alarm, rtc_control);
  62         else {
  63                 mo = cmos_bcd_read(RTC_MONTH, rtc_control);
  64                 today = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
  65         }
  66         if (acpi_gbl_FADT.century)
  67                 cent = cmos_bcd_read(acpi_gbl_FADT.century, rtc_control);
  68
  69         yr = cmos_bcd_read(RTC_YEAR, rtc_control);
  70
  71         spin_unlock_irqrestore(&rtc_lock, flags);
  72
  73         /* we're trusting the FADT (see above) */
  74         if (!acpi_gbl_FADT.century)
  75                 /* If we're not trusting the FADT, we should at least make it
  76                  * right for _this_ century... ehm, what is _this_ century?
  77                  *
  78                  * TBD:
  79                  *  ASAP: find piece of code in the kernel, e.g. star tracker driver,
  80                  *        which we can trust to determine the century correctly. Atom
  81                  *        watch driver would be nice, too...
  82                  *
  83                  *  if that has not happened, change for first release in 2050:
  84                  *        if (yr<50)
  85                  *                yr += 2100;
  86                  *        else
  87                  *                yr += 2000;   // current line of code
  88                  *
  89                  *  if that has not happened either, please do on 2099/12/31:23:59:59
  90                  *        s/2000/2100
  91                  *
  92                  */
  93                 yr += 2000;
  94         else
  95                 yr += cent * 100;
  96
  97         /*
  98          * Show correct dates for alarms up to a month into the future.
  99          * This solves issues for nearly all situations with the common
 100          * 30-day alarm clocks in PC hardware.
 101          */
 102         if (day < today) {
 103                 if (mo < 12) {
 104                         mo += 1;
 105                 } else {
 106                         mo = 1;
 107                         yr += 1;
 108                 }
 109         }
 110
 111         seq_printf(seq, "%4.4u-", yr);
 112         (mo > 12) ? seq_puts(seq, "**-") : seq_printf(seq, "%2.2u-", mo);
 113         (day > 31) ? seq_puts(seq, "** ") : seq_printf(seq, "%2.2u ", day);
 114         (hr > 23) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", hr);
 115         (min > 59) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", min);
 116         (sec > 59) ? seq_puts(seq, "**\n") : seq_printf(seq, "%2.2u\n", sec);
 117
 118         return 0;
 119 }
 120
 121 static int acpi_system_alarm_open_fs(struct inode *inode, struct file *file)
 122 {
 123         return single_open(file, acpi_system_alarm_seq_show, PDE(inode)->data);
 124 }
 125
 126 static int get_date_field(char **p, u32 * value)
 127 {
 128         char *next = NULL;
 129         char *string_end = NULL;
 130         int result = -EINVAL;
 131
 132         /*
 133          * Try to find delimeter, only to insert null.  The end of the
 134          * string won't have one, but is still valid.
 135          */
 136         if (*p == NULL)
 137                 return result;
 138
 139         next = strpbrk(*p, "- :");
 140         if (next)
 141                 *next++ = '\0';
 142
 143         *value = simple_strtoul(*p, &string_end, 10);
 144
 145         /* Signal success if we got a good digit */
 146         if (string_end != *p)
 147                 result = 0;
 148
 149         if (next)
 150                 *p = next;
 151         else
 152                 *p = NULL;
 153
 154         return result;
 155 }
 156
 157 /* Read a possibly BCD register, always return binary */
 158 static u32 cmos_bcd_read(int offset, int rtc_control)
 159 {
 160         u32 val = CMOS_READ(offset);
 161         if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
 162                 val = bcd2bin(val);
 163         return val;
 164 }
 165
 166 /* Write binary value into possibly BCD register */
 167 static void cmos_bcd_write(u32 val, int offset, int rtc_control)
 168 {
 169         if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
 170                 val = bin2bcd(val);
 171         CMOS_WRITE(val, offset);
 172 }
 173
 174 static ssize_t
 175 acpi_system_write_alarm(struct file *file,
 176                         const char __user * buffer, size_t count, loff_t * ppos)
 177 {
 178         int result = 0;
 179         char alarm_string[30] = { '\0' };
 180         char *p = alarm_string;
 181         u32 sec, min, hr, day, mo, yr;
 182         int adjust = 0;
 183         unsigned char rtc_control = 0;
 184
 185         if (count > sizeof(alarm_string) - 1)
 186                 return -EINVAL;
 187
 188         if (copy_from_user(alarm_string, buffer, count))
 189                 return -EFAULT;
 190
 191         alarm_string[count] = '\0';
 192
 193         /* check for time adjustment */
 194         if (alarm_string[0] == '+') {
 195                 p++;
 196                 adjust = 1;
 197         }
 198
 199         if ((result = get_date_field(&p, &yr)))
 200                 goto end;
 201         if ((result = get_date_field(&p, &mo)))
 202                 goto end;
 203         if ((result = get_date_field(&p, &day)))
 204                 goto end;
 205         if ((result = get_date_field(&p, &hr)))
 206                 goto end;
 207         if ((result = get_date_field(&p, &min)))
 208                 goto end;
 209         if ((result = get_date_field(&p, &sec)))
 210                 goto end;
 211
 212         spin_lock_irq(&rtc_lock);
 213
 214         rtc_control = CMOS_READ(RTC_CONTROL);
 215
 216         if (adjust) {
 217                 yr += cmos_bcd_read(RTC_YEAR, rtc_control);
 218                 mo += cmos_bcd_read(RTC_MONTH, rtc_control);
 219                 day += cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
 220                 hr += cmos_bcd_read(RTC_HOURS, rtc_control);
 221                 min += cmos_bcd_read(RTC_MINUTES, rtc_control);
 222                 sec += cmos_bcd_read(RTC_SECONDS, rtc_control);
 223         }
 224
 225         spin_unlock_irq(&rtc_lock);
 226
 227         if (sec > 59) {
 228                 min += sec/60;
 229                 sec = sec%60;
 230         }
 231         if (min > 59) {
 232                 hr += min/60;
 233                 min = min%60;
 234         }
 235         if (hr > 23) {
 236                 day += hr/24;
 237                 hr = hr%24;
 238         }
 239         if (day > 31) {
 240                 mo += day/32;
 241                 day = day%32;
 242         }
 243         if (mo > 12) {
 244                 yr += mo/13;
 245                 mo = mo%13;
 246         }
 247
 248         spin_lock_irq(&rtc_lock);
 249         /*
 250          * Disable alarm interrupt before setting alarm timer or else
 251          * when ACPI_EVENT_RTC is enabled, a spurious ACPI interrupt occurs
 252          */
 253         rtc_control &= ~RTC_AIE;
 254         CMOS_WRITE(rtc_control, RTC_CONTROL);
 255         CMOS_READ(RTC_INTR_FLAGS);
 256
 257         /* write the fields the rtc knows about */
 258         cmos_bcd_write(hr, RTC_HOURS_ALARM, rtc_control);
 259         cmos_bcd_write(min, RTC_MINUTES_ALARM, rtc_control);
 260         cmos_bcd_write(sec, RTC_SECONDS_ALARM, rtc_control);
 261
 262         /*
 263          * If the system supports an enhanced alarm it will have non-zero
 264          * offsets into the CMOS RAM here -- which for some reason are pointing
 265          * to the RTC area of memory.
 266          */
 267         if (acpi_gbl_FADT.day_alarm)
 268                 cmos_bcd_write(day, acpi_gbl_FADT.day_alarm, rtc_control);
 269         if (acpi_gbl_FADT.month_alarm)
 270                 cmos_bcd_write(mo, acpi_gbl_FADT.month_alarm, rtc_control);
 271         if (acpi_gbl_FADT.century) {
 272                 if (adjust)
 273                         yr += cmos_bcd_read(acpi_gbl_FADT.century, rtc_control) * 100;
 274                 cmos_bcd_write(yr / 100, acpi_gbl_FADT.century, rtc_control);
 275         }
 276         /* enable the rtc alarm interrupt */
 277         rtc_control |= RTC_AIE;
 278         CMOS_WRITE(rtc_control, RTC_CONTROL);
 279         CMOS_READ(RTC_INTR_FLAGS);
 280
 281         spin_unlock_irq(&rtc_lock);
 282
 283         acpi_clear_event(ACPI_EVENT_RTC);
 284         acpi_enable_event(ACPI_EVENT_RTC, 0);
 285
 286         *ppos += count;
 287
 288         result = 0;
 289       end:
 290         return result ? result : count;
 291 }
 292 #endif                          /* HAVE_ACPI_LEGACY_ALARM */
 293
 294 static int
 295 acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)
 296 {
 297         struct list_head *node, *next;
 298
 299         seq_printf(seq, "Device\tS-state\t  Status   Sysfs node\n");
 300
 301         mutex_lock(&acpi_device_lock);
 302         list_for_each_safe(node, next, &acpi_wakeup_device_list) {
 303                 struct acpi_device *dev =
 304                     container_of(node, struct acpi_device, wakeup_list);
 305                 struct device *ldev;
 306
 307                 if (!dev->wakeup.flags.valid)
 308                         continue;
 309
 310                 ldev = acpi_get_physical_device(dev->handle);
 311                 seq_printf(seq, "%s\t  S%d\t%c%-8s  ",
 312                            dev->pnp.bus_id,
 313                            (u32) dev->wakeup.sleep_state,
 314                            dev->wakeup.flags.run_wake ? '*' : ' ',
 315                            (device_may_wakeup(&dev->dev)
 316                              || (ldev && device_may_wakeup(ldev))) ?
 317                                "enabled" : "disabled");
 318                 if (ldev)
 319                         seq_printf(seq, "%s:%s",
 320                                    ldev->bus ? ldev->bus->name : "no-bus",
 321                                    dev_name(ldev));
 322                 seq_printf(seq, "\n");
 323                 put_device(ldev);
 324
 325         }
 326         mutex_unlock(&acpi_device_lock);
 327         return 0;
 328 }
 329
 330 static void physical_device_enable_wakeup(struct acpi_device *adev)
 331 {
 332         struct device *dev = acpi_get_physical_device(adev->handle);
 333
 334         if (dev && device_can_wakeup(dev)) {
 335                 bool enable = !device_may_wakeup(dev);
 336                 device_set_wakeup_enable(dev, enable);
 337         }
 338 }
 339
 340 static ssize_t
 341 acpi_system_write_wakeup_device(struct file *file,
 342                                 const char __user * buffer,
 343                                 size_t count, loff_t * ppos)
 344 {
 345         struct list_head *node, *next;
 346         char strbuf[5];
 347         char str[5] = "";
 348         unsigned int len = count;
 349
 350         if (len > 4)
 351                 len = 4;
 352         if (len < 0)
 353                 return -EFAULT;
 354
 355         if (copy_from_user(strbuf, buffer, len))
 356                 return -EFAULT;
 357         strbuf[len] = '\0';
 358         sscanf(strbuf, "%s", str);
 359
 360         mutex_lock(&acpi_device_lock);
 361         list_for_each_safe(node, next, &acpi_wakeup_device_list) {
 362                 struct acpi_device *dev =
 363                     container_of(node, struct acpi_device, wakeup_list);
 364                 if (!dev->wakeup.flags.valid)
 365                         continue;
 366
 367                 if (!strncmp(dev->pnp.bus_id, str, 4)) {
 368                         if (device_can_wakeup(&dev->dev)) {
 369                                 bool enable = !device_may_wakeup(&dev->dev);
 370                                 device_set_wakeup_enable(&dev->dev, enable);
 371                         } else {
 372                                 physical_device_enable_wakeup(dev);
 373                         }
 374                         break;
 375                 }
 376         }
 377         mutex_unlock(&acpi_device_lock);
 378         return count;
 379 }
 380
 381 static int
 382 acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
 383 {
 384         return single_open(file, acpi_system_wakeup_device_seq_show,
 385                            PDE(inode)->data);
 386 }
 387
 388 static const struct file_operations acpi_system_wakeup_device_fops = {
 389         .owner = THIS_MODULE,
 390         .open = acpi_system_wakeup_device_open_fs,
 391         .read = seq_read,
 392         .write = acpi_system_write_wakeup_device,
 393         .llseek = seq_lseek,
 394         .release = single_release,
 395 };
 396
 397 #ifdef  HAVE_ACPI_LEGACY_ALARM
 398 static const struct file_operations acpi_system_alarm_fops = {
 399         .owner = THIS_MODULE,
 400         .open = acpi_system_alarm_open_fs,
 401         .read = seq_read,
 402         .write = acpi_system_write_alarm,
 403         .llseek = seq_lseek,
 404         .release = single_release,
 405 };
 406
 407 static u32 rtc_handler(void *context)
 408 {
 409         acpi_clear_event(ACPI_EVENT_RTC);
 410         acpi_disable_event(ACPI_EVENT_RTC, 0);
 411
 412         return ACPI_INTERRUPT_HANDLED;
 413 }
 414 #endif                          /* HAVE_ACPI_LEGACY_ALARM */
 415
 416 int __init acpi_sleep_proc_init(void)
 417 {
 418 #ifdef  HAVE_ACPI_LEGACY_ALARM
 419         /* 'alarm' [R/W] */
 420         proc_create("alarm", S_IFREG | S_IRUGO | S_IWUSR,
 421                     acpi_root_dir, &acpi_system_alarm_fops);
 422
 423         acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
 424         /*
 425          * Disable the RTC event after installing RTC handler.
 426          * Only when RTC alarm is set will it be enabled.
 427          */
 428         acpi_clear_event(ACPI_EVENT_RTC);
 429         acpi_disable_event(ACPI_EVENT_RTC, 0);
 430 #endif                          /* HAVE_ACPI_LEGACY_ALARM */
 431
 432         /* 'wakeup device' [R/W] */
 433         proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
 434                     acpi_root_dir, &acpi_system_wakeup_device_fops);
 435
 436         return 0;
 437 }